During the past year, we have continued to process the diagnostic data, develop codebooks, and create secondary variables for analysis. Several active NCS-A work groups have been formed, including experts in the field from both intramural and extramural collaborators. Working with these experts, we have devoted substantial efforts to investigate a wide range of mental health topics in adolescents. These efforts have yielded several manuscripts, both published and in progress, including: (1) the prevalence of mental disorders in the U.S. adolescent population (Merikangas et al., 2010);(2) service patterns for mental disorders among these youth (Merikangas et al., 2011);and (3) comprehensive, disorder and topic-specific papers that examine mania, major depression, anxiety (Merikangas et al, in preparation;Lamers et al, submitted;Burstein et al., 2011), and eating disorders (Swanson et al., 2010), as well as migraine (Nakamura et al., 2011), suicide (Husky et al, in press), tobacco use (Dierker et al, in press), substance use disorders (Swendsen et al., in press), and child neglect (Heaton et al, in preparation). Other analyses that have been conducted and submitted for publication include: (1) A latent class analysis (LCA) of lifetime anxiety disorders among U.S. adolescents. (2) The overlap of shyness and social phobia in U.S. adolescents. (3) A latent class analysis (LCA) examining the structure of depression in U.S. adults and adolescents. (4) Alcohol and drug use, abuse, and dependence in U.S. adolescents. (5) The presentation of eating disorder NOS in the U.S. population. (6) Frequency and quantity of polysubstance use among U.S. adolescents. (7) The relationship between bulimia and suicide among U.S. adolescents. (8) The timing of smoking transitions in risk for regular smoking and nicotine dependence among U.S. adolescents. (9) The prevalence and physical comorbidity of migraine and other headache in U.S. adolescents. (10) Suicidal ideation and service use in U.S. adolescents. (11) Psychotropic medication use of U.S. adolescents. In addition, we are currently preparing several other manuscripts for submission on a range of topics, including: (1) The phenomenology and typology of specific phobia in U.S. adolescents. (2) The spectrum of mania and depression in U.S. adolescents. (3) The prevalence and correlates of major depression in U.S. adolescents. (4) Ethnic differences in eating disorders. (5) The prevalence of DSM-5 substance use disorders and their concordance with DSM-IV diagnoses in U.S. adolescents. (6) Services for mental disorders by race and ethnicity among U.S. adolescents. (7) Medication use by psychiatric diagnosis among U.S. adolescents. (8) The prevalence of migraine among U.S. adolescents. (9) The Strengths and Difficulties Questionnaire and its relationship with mental disorders and service use in U.S. adolescents. (10) The factor structure and scale validation of the Strengths and Difficulties Questionnaire (SDQ) in U.S. adolescents. Public Health Impact: Aside from providing the first prevalence data on a wide range of psychiatric disorders in a nationally representative sample of U.S. adolescents, the results of this study demonstrate that common mental disorders in adults first emerge in childhood and adolescence. The severity of disorders under study is also demonstrated by the high degree of comorbidity, clinical distress, role impairment, and suicidality among youth with mental disorders. Due to the substantial proportion of young people with severe mental disorders that have never received specialty mental health care and the marked racial disparities in lifetime mental health treatment for mood and anxiety disorders, the magnitude of unmet needs in mental health treatment are of great importance in public health. Our results further highlight the need for a transition from the common focus on treatment of U.S. youth to that of prevention and early intervention. Future work on this rich resource will help to address the dramatic personal and societal impact of adolescent mental disorders in order to help establish sound public health policy and design health programs and services. Future Plans: During the next year, we plan to: (1) expand our understanding of mental disorders and service utilization in adolescents by examining risk and protective factors at the level of the individual, family, and community;(2) investigate the role of immigration and school/neighborhood factors on mental disorders in youth;(3) examine patterns of comorbidity between mental and physical disorders;(4) conduct analyses among subgroups linking data from other national and international studies, as well as geocoding;and (5) complete the salivary stress hormone assays and evaluate their association with mental disorders in adolescents.